What is Bitcoin? Bitcoin is a decentralized, peer-to-peer digital currency and monetary network launched in 2009. It enables users to transfer value without a central bank or payment company by combining public-key cryptography, a distributed ledger, and proof-of-work consensus.
How Bitcoin works
Bitcoin uses a public blockchain replicated across independent network nodes. Transactions are recorded in chronological blocks, and each block references the hash of the previous one, making historical changes computationally expensive. Full nodes independently verify transactions, signatures, block rewards, and consensus rules rather than trusting a central operator.
The network uses an unspent transaction output, or UTXO, model instead of conventional account balances. Transactions consume existing UTXOs and create new outputs controlled by conditions linked to private-key signatures. The difference between transaction inputs and outputs becomes the fee paid to the miner.
Mining uses repeated SHA-256 hashing. Miners vary data in a block header until they produce a hash below the network’s difficulty target. Blocks are created roughly every 10 minutes, while difficulty adjusts every 2,016 blocks to keep production close to its intended schedule.
Bitcoin’s base layer prioritizes settlement, auditability, and decentralization rather than high transaction throughput. Taproot, activated in 2021, improved script flexibility, transaction efficiency, and certain privacy characteristics. The Lightning Network adds a second layer using payment channels to support faster and potentially lower-cost payments, including micropayments, while using the blockchain for settlement and dispute resolution.
What is Bitcoin used for?
Bitcoin is used as a peer-to-peer payment system, a cross-border settlement asset, and a digitally scarce store of value. Individuals can hold and transfer it directly through wallets without requiring a bank, although exchanges, custodians, and payment processors also provide access and storage services.
Businesses and institutions use BTC for treasury holdings, collateral, settlement, and investment exposure. In the United States, spot Bitcoin exchange-traded products were approved on 10 January 2024. BlackRock’s iShares Bitcoin Trust reported net assets of $66,881,750,049 as of 29 September 2026. Strategy reported holding 843,775 bitcoin as of 26 July 2026.
Bitcoin is also used in payment and remittance infrastructure. Lightning supports transactions away from the base chain, while on-chain transfers provide globally accessible settlement. El Salvador adopted Bitcoin as legal tender on 7 September 2021, although IMF assessments found limited use in payments and remittances.
Who is behind Bitcoin and where is it based?
Bitcoin was introduced by Satoshi Nakamoto, the pseudonymous author of the whitepaper “Bitcoin: A Peer-to-Peer Electronic Cash System,” published on 31 October 2008. The genesis block was mined on 3 January 2009. Nakamoto’s identity, country of residence, and legal identity have not been conclusively established.
Early contributors included Hal Finney and Gavin Andresen, alongside other open-source developers. Bitcoin development now takes place through a distributed community, with Bitcoin Core serving as a major open-source implementation. There is no confirmed company, foundation, headquarters, or national operating entity that owns or controls the Bitcoin network. Bitcoin Core is software, not the legal owner of Bitcoin, and network participants decide which compatible software and consensus rules to run.
Tokenomics and supply
Bitcoin’s protocol defines a maximum issuance of 21 million BTC. New coins enter circulation through mining subsidies, while miners also receive transaction fees. The subsidy began at 50 BTC per block and halves every 210,000 blocks, approximately once every four years.
The latest halving occurred at block 840,000 in April 2024, reducing the reward to 3.125 BTC. The next halving is expected around 2028 at block 1,050,000, reducing the reward to 1.5625 BTC. This declining issuance creates disinflationary monetary mechanics, while lost private keys can make coins inaccessible without formally removing them from the blockchain.
Bitcoin was distributed through mining rather than a corporate presale or foundation treasury. CoinStats recorded a circulating supply of 20,090,909 BTC and a total supply of 20,090,909 BTC on 1 October 2026. The market snapshot listed a price of $83,618.20, a 24-hour change of -0.05%, a market cap of $1.68T (rank #1), 24-hour volume of $34.38B, and an all-time high of $126,080.00, the current price is 33.68% below it.
Consensus and network security
Bitcoin uses proof of work, not proof of stake. Miners compete by expending computing power and electricity to produce valid blocks. Nodes independently verify each block and generally follow the valid chain with the greatest cumulative proof of work.
Security comes from cryptographic signatures, independent node validation, mining costs, competition among miners, and the difficulty-adjustment mechanism. Reversing confirmed transactions would require an attacker to recreate the targeted work and catch up with the honest network. Mining-pool concentration and majority-hashrate attacks remain structural risks, although an attacker cannot create unlimited BTC or spend coins without valid private keys.
Ecosystem integrations and advantages
Bitcoin has no central partnership program. Its ecosystem includes exchanges, hardware and software wallets, custodians, payment processors, mining pools, specialized hardware manufacturers, node operators, institutional investment products, and Lightning implementations. Integrations are permissionless and do not represent partnerships with a central Bitcoin company.
Its main advantages are fixed issuance, global portability, public auditability, censorship resistance, open participation, deep liquidity, and a long operating history since 2009. Its limitations include energy-intensive mining, public transaction records, private-key loss risks, variable fees, limited base-layer throughput, and the coordination required for protocol changes.
Current development activity
Bitcoin development is open-source and conservative, with work focused on node efficiency, validation performance, transaction relay, wallet functionality, peer-to-peer networking, privacy, and Lightning reliability. Bitcoin Core releases are developed through public review and testing, but a software release does not automatically change the rules for every participant.
Active areas of debate include OP_RETURN relay policy, covenant proposals, and quantum-resistance research such as BIP-360. These remain proposals or research topics rather than activated consensus changes. Any consensus-affecting upgrade requires implementation, testing, and broad adoption by users, miners, businesses, and node operators.